1. Field of the Invention
The present invention relates to a process of producing calcium aluminate monosulfate hydrate (3CaO.Al.sub.2 O.sub.3.CaSO.sub.4.12H.sub.2 O) (hereinafter, the compound is referred to as MSH in this specification).
2. Description of the Prior Art
It has hitherto been known that MSH is produced by mixing calcium oxide (CaO), alumina (Al.sub.2 O.sub.3), and calcium sulfate (CaSO.sub.4) at a ratio almost same as the mole ratio in 3CaO.Al.sub.2 O.sub.3.CaSO.sub.4, burning the mixture at temperatures of 900-1450.degree. C. to provide a solid solution of 3CaO.3Al.sub.2 O.sub.3.CaSO.sub.4 (hereinafter, is referred to as C.sub.4 A.sub.3 S), adding thereto predetermined amounts of a lime component, a gypsum component and water, and then subjecting the resulting mixture to a hydration reaction for a long period of time.
However, since the conventional process requires a step of high-temperature burning, the cost of equipment becomes higher and also the amount of energy required for finishing the process becomes larger. Furthermore, the process has such faults that the reaction period of time required is longer and the purity of MSH produced is low as, for example, lower than 50%.